I/O maintenance in brackish/salt water

[Nautiqueboy]

what is the typical maintenance required for an I/O in brackish/salt water besides a fresh water flush of the system after use. Also do they have a heat exchanger system available that uses antifreeze in the engine and salt water running over the exchanger to keep salt water out of the engine?

 

[Espos4]

During the season, a fresh water flush like you mentioned and keep an eye on the anodes.

Every off season, I remove my outdrive.
Oil change, split upper from lower unit, clean barnacles from the water way, scrape and paint inside and out with Trilux.

Adding fresh water cooling to a used salt water engine can cause clogging of the heat exchanger and it may need constant flushing.

 

[El Capitan]

what is the typical maintenance required for an I/O in brackish/salt water besides a fresh water flush of the system after use. Also do they have a heat exchanger system available that uses antifreeze in the engine and salt water running over the exchanger to keep salt water out of the engine?

Depending on if you wet slip or trailer/dry stack.

I hope you don’t wet slip an IO in salt. I did in “brackish” and I was far up the river to think the water was mainly fresh. Wrong.

I thought the ride up the river In brackish was the flush. Wrong.

Salt and IOs don’t go together. See large Sea Rays w IO setups in Great Lakes and fresh water regions as common vs in SE where ocean use is standard.

Not saying people don’t do it but it requires diligence in maintaining the drive on a constant basis.

Ask me how I know!

I recommend you use a salt away type product for flushing and make sure you flush long enough for thermostat to open. That’s when the flushing starts.

Pull drive every year and service gimbal bearing.

Drop lower unit every year change impeller.

Change lower unit oil every year.

Inspect dogs/clutches every year.

Service and repairs accordingly.

 

[Nautiqueboy]

I wonder if an outboard will do better in brackish water. I have an inboard on the river and it has been maintenance intensive with corrosion issues. I have an inboard on a lake and I have never replaced the manifolds from factory, and that boat was made in 1985!

 

[b_arrington]

what is the typical maintenance required for an I/O in brackish/salt water besides a fresh water flush of the system after use. Also do they have a heat exchanger system available that uses antifreeze in the engine and salt water running over the exchanger to keep salt water out of the engine?

With reasonable care, an outdrive-equipped boat stored in salt water can be very reliable and last a long time. Mine is 12 years old and in excellent condition. A you noted, inboards can have issues as well.

Since you seem to have more experience with inboards, here's some background. Outdrive setups are available in 2 general versions: raw-water cooled and fresh water cooled.

• Raw water: raw water is circulated through the entire system. If in salt, that's what you use. It is possible to add a heat exchanger, but it's usually only a partial system.
• Fresh water (Mercruiser "Horizon" engines): Raw water is used in a heat exchanger, and engine coolant is circulated through the block, etc. Generally raw water has very limited contact with the engine itself, and is dumped back into the exhaust risers.

Sea Rays used Mecruiser engines. Here you have 2 types of drives: Alpha and Bravo. Alpha is older, single prop and for lighter boats. The water pump is in the drive - hence the suggestion to split the drive and replace the impeller annually.

Bravo is for heavier boats and comes in a couple versions. Brave II is single prop. Bravo III is dual stainless props. All Bravos have engine-mounted water pumps - you don't split the drive. Most take water in through the drive leg. This water hose can and will evenutally get gunked up with salt build up and need to be corrected. Some (like mine) have a through hull water intake that bypass the drive leg entirely - much better setup.

Early Bravo III models had a corrosion problem due to the amount of stainless steel on the props near the aluminum drive. This was corrected with a new design that added more zincs. Boats with the older design can be protected by carefully monitoring anode consumption and ensuring the Mercathode system is functioning.

The most important thing about outdrive maintenance in salt water is protecting against galvanic corrosion. Check your zincs, replace as needed right away. You do need to remove the drive annually to service it and check the boots / bellows, etc.

Are outboards better? That depends. All engines can have issues. My brother-in-law has had a ton of problems with his. There is merit to the the idea that they are selt-contained, self-draining and and be tilted out of the water. It all depends on what you want out of boat.

 

[Gregory Beach]

Depending on if you wet slip or trailer/dry stack.

I hope you don’t wet slip an IO in salt. I did in “brackish” and I was far up the river to think the water was mainly fresh. Wrong.

I thought the ride up the river In brackish was the flush. Wrong.

Salt and IOs don’t go together. See large Sea Rays w IO setups in Great Lakes and fresh water regions as common vs in SE where ocean use is standard.

Not saying people don’t do it but it requires diligence in maintaining the drive on a constant basis.

Ask me how I know!

I recommend you use a salt away type product for flushing and make sure you flush long enough for thermostat to open. That’s when the flushing starts.

Pull drive every year and service gimbal bearing.

Drop lower unit every year change impeller.

Change lower unit oil every year.

Inspect dogs/clutches every year.

Service and repairs accordingly.

Hey there, sir-

Sorry to revive such an old thread. New to boating, have had our '12 310DA for two years and just realized as I learned more about our systems it's RWC with no exchanger. Didn't now enough about our setup beforehand, and it was never mentioned/clarified to us despite being new to boating we would need to flush regularly. Any suggestions to flushing, or creating a sort of a quick-connect system with salt away and water from our main water supply in the boathouse?

What other concerns should I have if it's been two years and unless it's been done at annual service (all service has been regular), it's been mooring year-round?

Thanks for any insight, and pity

You live and learn, right?
-Greg

 

[El Capitan]

Hey there, sir-

Sorry to revive such an old thread. New to boating, have had our '12 310DA for two years and just realized as I learned more about our systems it's RWC with no exchanger. Didn't now enough about our setup beforehand, and it was never mentioned/clarified to us despite being new to boating we would need to flush regularly. Any suggestions to flushing, or creating a sort of a quick-connect system with salt away and water from our main water supply in the boathouse?

What other concerns should I have if it's been two years and unless it's been done at annual service (all service has been regular), it's been mooring year-round?

Thanks for any insight, and pity

You live and learn, right?
-Greg

That’s a tough one. Flushing is only a part of it. Growth on the surfaces of your outdrives, on the inside of the drive, your drive seals it’s just a long list of maintenance that you need to be on top of when in salt especially electrolysis.

Haul the boat out, inspect and proceed based on observations and any deferred maintenance.

Good luck.